The 'power dissipation' in a Cass C stage is primarily a function of
what
percentage of the cycle the stage is neither in saturation nor
cutoff. A
perfectly rectangular output switching waveform of any duty cycle ,
if it
could be achieved, would result in nearly 100% efficiency.

Joe
W3JDR
===================================

Unfortunately, it makes a terrible mess of any modulation.

To avoid distortion and non-linearity, saturation can be permitted
only on the extreme peaks of the modulated driving waveform. Class-C
is ruled out. Class-B or Class-AB prevails.
----
Reg.